I've got an old aluminum MTB (Gary Fisher Tassajara) that makes a metallic popping sound when I bounce on the seatThe sound is coming from the frame at the top of the seat tubeIt still does this with a different seat/postThere are no visible cracks anywhereEverything is greased and torqued properlyCan this be something other than a cracked frame? It has an over sized seat tube that tapers down at the topCan something be cracked internally?
A.CMoore, Mary Maxim, HerschnerrsThey all have online sitesIf worse came to worse, you can buy a large spool of Lily Sugar and Cream cotton yarn in white and dye it to the colors you wantAlso, you could use something called ombre yarn that will give the effect of tie dye.
Aluminum frames often make creaking noises but it is better to be safe than sorryDid you lubricate the seat post before installing it? Before going crazy, take a fingerful of lithium grease and wipe it into the seat tube then install the postRemove the stem from the steerer and do the same thingCheck to make sure the bottom bracket is properly seated and the crank arms are installed correctlyTake off the pedals and lube the threadsLook very closely at the following areas: - all along the seat tube - where the chainstays meet the bottom bracket - the chain stay reinforcement -the rear dropouts A crack may appear as a very thin long scratch so it is probably a good idea to use a magnifying glass for inspectionIf the frame is cracked it likely will NOT be covered under warrantyMost cracks that are warranted are tubing cracks, not cracks at welds Aluminum has a limited life and as such will eventually fail no matter how you ride.
I've seen some at Michaels beforeRed Heart.
